Historically in Western culture, marriage proposals were strictly gendered and it was the duty of the man to propose to the woman. In some countries, a tradition evolved to get around this one-sided mechanism and give women a chance to propose.

In Britain (as well as Ireland, Scotland, and Finland), there’s a long-standing tradition that during a leap year—a year that features an extra day to adjust for issues with the Gregorian calendar—woman may propose to their mate of choice. In some places and by some variations of the tradition, it is restricted to just the leap day itself, February 29, but the window of time on the tradition isn’t fixed. The image of an old postcard from 1908, seen here, suggests that proposals are fair game for the entire year.

There’s no consensus on where exactly the tradition started or how. A popular, but completely unverified, story regarding the origin of the tradition claims that it dates all the way back to the 5th century. There, the story goes, St. Brigid (Brigid of Kildare), an Irish nun, complained to St. Patrick that women were stuck waiting too long for suitors to get their act together and propose marriage. The two reached an agreement wherein St. Patrick decreed that the leap year should be a time for women to reverse roles and propose.

That’s a fun story, but considering there’s no written account of the tradition before the 19th century, and the whole tradition itself seems to date from around the same time, there’s not a whole lot shoring up that particular account of things. None the less, the tradition itself is an interesting bit of matrimonial trivia and an interesting reflection on the history of courtship.